The term “pressure filling” in the sense of the invention generally means a filling method in which the container to be filled lies tightly against the filling element and usually before the actual filling phase, i.e. before opening of the liquid valve, is pre-tensioned via at least one controlled gas path formed in the filling element with a compressed tension gas (inert gas or CO2 gas) which then during filling is increasingly displaced from the container interior as a return gas, also via at least one controlled gas path formed in the filling element, by the filling material flowing into the container. This pre-tension phase can be preceded by further treatment phases, for example an evacuation and/or flushing of the container interior with an inert gas e.g. CO2 gas etc., also via the gas paths formed in the filling element.
The term “pressureless filling” in the sense of the invention generally means a filling method in which the container to be filled lies preferably with its container mouth also tightly against the respective filling element and the container interior, before the actual filling phase i.e. before opening of the liquid valve, is pre-treated for example evacuated and/or flushed with an inert gas for example CO2 gas via controlled gas paths formed in the filling element, wherein then during filling the gas increasingly expelled by the filling material flowing into the container is discharged from the container interior as a return gas via at least one controlled gas path formed in the filling element.
“Containers lying tightly against the filling element” in the sense of the invention means that the container to be filled lies in a manner known to the person skilled in the art with its container mouth tightly against the filling element or pressed against the seal present there and surrounding the at least one discharge opening of the filling element.
“Containers” in the sense of the invention are in particular cans and bottles of metal, glass and/or plastic, but also other packing means which are suitable for filling with liquid or viscous products for pressure filling or for pressureless filling.
The term “substantially” in the sense of the invention means deviations from the precise value by +/−10%, preferably by +/−5%, and/or deviations in form of changes irrelevant to function.
In known filling machines, in particular those of circulating design in which the filling points are provided on a transport element in the form of a rotor that can be driven circulating about a vertical machine axis, the filling elements each have several controllable gas paths each with at least one control valve per gas path, for example three such control valves, to achieve a high flexibility for the filling machine i.e. in order in particular to allow different filling methods optimally adapted to the respective product such as pressure filling, pressureless filling etc. with different treatment phases, in particular also with different pre-treatment and post-treatment phases, such as for example evacuation and/or flushing of the respective container interior before opening the liquid valve, and/or settling of the filling material and/or pressure relief of the container interior after closing of the liquid valve etc. The plurality of control valves means a substantial complexity in construction, assembly and control technology.